Sound amplifier or megaphone tone box



Jan. 18,1927. J. L. WRIGHT lSOUND AMPLIFIER 0R MEGAPHONE Toms:V Box Filed Oct. 6

Patented Jan. 18, 1927.

UNITED STATES PATENT OFFICE.

SOUND AMPLIFIER OR MEGAPHONE TONE BOX.

Application filed October 6, 1924. Serial No. 741,853.

My invention belongs to that general class ot devices designed to be employed with sound or musical instruments of various kinds, such, for illustration, phonographs and similar devices, and including use also with radio apparatus, together with such other use as it may be adapted to.

It has for its object not only the amplification of musica-l or other tones, but also a modification of the tone itself by means ot' which musical tones, for illustration, are much more softened and agreeable, and the harsher tones thus obviated.

To this end my invention consists in the novel construction, arrangement and combination of parts herein shown and described, and more particularly pointed out in the claims.

In the drawings, wherein like reference characters indicate like or corresponding parts- Fig. 1 is a section through a phonograph disclosing the usual tone arm and showing a suitable connection of my invention theren with to secure the advantages thereof;

Fig. 2 is a central vertical section through a part of my device, substantially on the line 2 2 of Fig. 3, showing my improved resonant or tone box in position;

Fig. 3 is a transverse section on line 3*?) of Fig. 2;

Fig. 4 is a section on line 4--4 of Fig. 2; and

Fig. 5 is a perspective view of one form oi the resonant wall member 6.

Referring to the drawings, 1 illustrates the usual tone arm of the phonograph. in position extending through the table or support 2 in the usual manner. Arranged beneath the supported end of the tone arm is my improved device, which in the form preferably employed comprises the vertical tone arm 3, at its lower part opening into the horizontal extension 4f substantially at a right angle, the floor 5 being substantially horizontal. Arranged substantially within the vertical portion 3, as shown, is positioned my resonant or tone box l0 provided with a wall member' 6 which at its upper end is secured to the rear of the arm 3 as at 7, being upwardly extended and preferably merged into the said wall at the upper end as indicated. The free end of this wall 6 is extended outwardly from the wall 3, preferably in a diagonal direction and at a curve, as shown, at its lower end 8 being slightly spacer above the floor wall 5 as at 9. This construction provides a hollow chamber l0 which is provided on the sound side of the device with the resonant wall 6 ot' suitable material.

In actual practice I have secured satisfactory results by making the resonant wall 6 ot some character of soft wood, such, for example, as cedar, white pine, etc. To secure the most satisfactory results, the resonant member G should be well seasoned and free ot' knots, shakes or other imperfect-ions which would interfere with its perfect vibration.

I have also secured exceedingly satisfactory results by grooving the interior side of the resonant member 6 as shown at ll in F ig. This apparently effects a marked improvement in the tone, although I have secured very satisfactory results without having the board grooved.

Thus the device which in its entirety is preferably formed of suitable wood or equivalent material for the purpose, is firmly glued and secured together' with the sound board (3 secured to the part 3 at the back and through the edges of the board. through the sides. Thus the sound board 6 is entirely supported by the walls of the amplifier, preferably leaving` the free ends spaced as at 9. I have had satisfactory results in making the amplifier of a goed grade of cedar with the sound board either of white pine or cedar. Other equivalent material can undoubtedly be used when desired.

I discovered by the use of .my device that the sound of an ordinary phonograph will be carried several blocks and be heard with the greatest distinct-ness, while at the same time when close to the device, the tones are so softened that there is apparently no objectionable increase in the. loudness or volume of the instrument. I have further discovered that the length of the tone arm sound board 6 has a pronounced eilect upon the pitch of the tones, and while the harshness and disagreeable portions ot the notes are removed, a short arm seems to give ahigher pitch, while thc longer arm gives a deeper and more sonorous tone.

In actual practice I have used my device in a large dance hall upon an ordinary phonograph, and the result. has been most satisfactory in every way.

lith slight modification my device can be adapted for use with radio devices, as is obvious, and therefore l desire to be understood as including' such use therewith. as well as such other use as it ma'v be adapted for.

Fic'. 5 shows a form of resonant member ,that has produced very satisfactory results.

In this form the ineinber is preferablv of such width as to snugly lit within the upright arm 9) and be suitablv secured both to the back wall as well as the side walls thereof. The back wall thus forms one wall of the tone chamber. with the bottom sli-rg'htl)v spaced above the approximate bottom wall.

The form of amplifier or inec'aphone mav be greatly varied. so loneA as it embodies mv improved tone chamber as described.

Haviim` thus described nrv invention` it is obvious that various other immaterial modifications 1na v be made in the same withoutI departing' from the spirit of in v invention; hence l do not wish to he understood limitincv myself to the exact form. construction, arrangement and combination of parts herein shown and described, or uses men tioned.

lllhat l claim new and desire to secure b v Letters Patent is:

l. A device of the kind described comprising an amplifier device to receive sound tones from a source, in combination with a resonant member connected onl;T at one end and the side walls to the inside of the wall of the inegaphone of the amplifier and extending' outward therefrom to provide a tone chamber, closed at one end and two sides and open at the remaining' end.

2. A device of the kind described` comprisinean amplifier device comprising a vertical section and an angular section secured thereto, and extending horizontally with respect to the said vertical section. the vertical section to receive sound tones from a source. in combination with a resonant member connected at one end to the inside of the wall of the vertical section of the receiving arm and extending' inclinedlv downward from the point of connection and inward from said wall to provide a tone chamber, said resonant member beiner closed except at the free end thereof which is spaced from the proximate wall of the horizontal member of the device to define an opening' between the lower portion onl v of the resonant member and the said horizontal member.

23. in amplifier member for sound producin;l devices comprising a hollow receiving arm to receive tones from a source` in combination with a tone partition wall within and connected to said arm at one end and extending' therefrom to pro vide a tone chamber with the free end thereof open and slightly spaced from the adiacentpwall of the device, and connected to the arm to make a tone box open onlx7 at its free end.

et. In a device of the kind described, a receiving' arm, in combination with a closed and imperforate tone box at one end at two sides secured thereto and extending' therefrom to in 'ovide a tone chamber with the free open end of the tone arm spaced from the adjacent wall of the device.

5. ln a device of the kind described, a receiving arm. in coi'nbination with a tone box one end of which is secured thereto and extends therefrom to provide a tone chamber, closed at all points except the free end which is open.

6. ln a device of the kind described, a receiving arm having' an angular wall at one end in combination with an imperforate nrooved tone member G within the same. closedlv secured at one end and the sides thereto and extending' therefrom to provide a tone chamber l0, the groovcd side of the member G facingl the tone chamber.

T. In a device of the kind described7 a receiving' arm havinc` an angular wall at one end in combination with an imperforate grooved tone member G within the same. closedl)7 secured at one end and the sides thereto and extending; therefrom to provide a tone chamber l0, the crooved side of the member 6 facing' the tone chamber, the free end of the member t3 beine' open and spaced from the adjacent angular wall.

8. A resonant member for amplifiers or erpiivalent devices provided with a bottom wall and side walls, comprising a member adapted to be secured to the wall of the device wit-h a hollow member having' a free open end at the bottom when in assembled position spaced fron'i the adjacent bottom wall, said member beine` wedge shape in general outline and formed with a longitudinal groove in one side. the bottom of which is parallel to the opposite inclined wall wherebjiT upon sec' ring' said member in position the grooved part will provide a tone chamber.

9. In a device of the class described, an amplifier consisting of a main chamber comprising a receiver arm at an angle to a poi'- tion of the main chamber and an auxiliary chamber9 said auxiliar-v chamber being mounted withinA the receiver arm and having' one end thereof secured to the wall of the said main chamber and extending' therefrom `and toward and to a point near the proximate wall and spaced from said proximate wall. the free end of the auxiliar)v chamber being provided with an opening; therein, said auxiliar;v chamber beiney closed except at the said free end thereof.

in tes monv whereof, l have hereunto signed my name.

JUDY LAPORTE WRIGHT. 

